Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets such as this one for Limestone County, Texas, and

Lipscomb County, Texas, give the percentage contributions from specific air pollution sources.  The Limestone County Seat is Groesbeck, Texas, and the Lipscomb County Seat is Lipscomb, Texas.